二体磨料磨损犁沟及脊的三维有限元动态模拟

3D Dynamic Simulation of Groove and Ridge in Two-Body Abrasive Wear by Finite Element Method

选用20#钢、45#钢、T8钢3种材料作为研究对象,利用三维有限元法动态模拟刚性球形磨粒在弹-线塑性平板上的压入-划动过程,所用磨粒半径为0.15mm,试样尺寸为1.2mm×1.2mm×3.0mm,划动距离1.2mm;采用ANSYS/LS-DYNA软件对每种材料在压入深度0.01～0.10mm范围内进行10次动态模拟.为验证模拟的有效性,在改装的HX-200型显微硬度计上进行单磨粒划伤试验,用OLS-1100型非接触式三维激光共聚扫描电子显微镜分析了相应的犁沟和脊.结果表明,模拟结果与试验结果相吻合,能够重现碳钢材料在磨损过程中的塑变行为,进而通过提取犁沟脊表面的节点坐标值,对材料犁沟两边塑变脊进行量化分析,得到脊形貌尺寸随磨粒压入深度、压入宽度和材料性能变化的规律,并建立了适用于碳钢系列材料塑变脊形貌与磨粒压入深度和宽度的关系曲线.

It is imperative to determine the factor differentiating the percentage of the wear debris volume from that of the total groove so as to realize the reliable prediction of the wear rate of materials. However, it is hard to determine this factor since it is difficult to express the groove and ridge morphologies. Thus a three-dimension finite element method (FEM) was used to analyze the simulation of the groove and ridge morphologies of a series mild carbon steel (AISI-1020, AISI-1045 and AISI-1080) samples subject to two-body abrasive wear. The simulation results were correlated and compared with the experimental ones based on single-tip scratch testing as well. Therefore, the stress and the strain of a half infinite plane indented by a sliding spheric tip were calculated based on an elastic-linear strengthened plastic deformation model, making use of a commercial software. The groove and ridge descriptions were fitted after the FEM simulation, while the scratched morphologies were analyzed on a laser coincident focus scanning electron microscope so as to evaluate the correlation between the theoretical results and the experimental results. It was found that the simulation results based on the FEM agreed well with the experimental ones. Thus the established theoretical model could be used to well predict the abrasive wear behavior of the mild steels.